Anti-government demonstrators celebrate in Tahrir Square upon hearing the news of the resignation of Egyptian President Hosni Mubarak on Feb. 11, 2011, in Cairo, Egypt. After 18 days of widespread protests, Mubarak, who has now left Cairo for his home in the Egyptian resort town of Sharm el-Sheik, announced that he would step down.

The smart people are advising caution.

OK. But let’s wait a day or two or more for that. The worried people are worried about everything that can go wrong. Much can go wrong, but today is not the day for worry.

Today is the day when all things are possible. The people let their Pharaoh go — and, for now anyway, everything we thought we knew about the Middle East has changed. The spark was lit by the Tunisian fruit seller who set himself afire. The flame leaped to Egypt, and though Hosni Mubarak thought he could withstand it, he couldn’t. A day after he pretended to quit, he quit in earnest. He had to quit or he had to be able to force the Army to take on the protesters. Friday would be the day. We just didn’t know when we woke what kind of day.

The revolution came when hundreds of thousands of protesters took to the streets in a country where the streets have forever belonged to the thuggish secret police. Tahrir Square now has the chance to be remembered like the tearing down of the Berlin Wall.

Demonstrators carry a huge Egyptian flag in Tahrir Square in Cairo, Egypt, Tuesday, Feb. 1, 2011. More than a quarter-million people flooded into the heart of Cairo Tuesday, filling the city's main square in by far the largest demonstration in a week of unceasing demands for President Hosni Mubarak to leave after nearly 30 years in power.

The crowds at Tahrir Square were shouting, “Not enough, not enough,” which is probably the perfect analysis of Hosni Mubarak’s not-enough, not-quite-resignation speech.

Mubarak is going. The question is when. And the usual rule is that the guy who’s being kicked out doesn’t get to decide. Mubarak says he won’t run for re-election (that would be to a seventh term, for those keeping score) in September. But September is way too late. You don’t keep the lid on crowds for months, particularly a crowd that is demanding Mubarak quit by Friday. And why, at this point, would anyone trust Mubarak, who is simply one step away from calling a national emergency and, uh, postponing the September election and prolonging his 30 years on the job?

This is a revolution, even if we don’t yet know what kind. If you listen to the experts, and to the crowds, the obvious solution is for Mubarak to name a date — a much earlier date than September — for new elections. Until then, there needs to be some kind of power-sharing. In this time, when the crowds still have influence, you have to hope that genuine pro-democracy people would play a role.

Anti-government protesters shout slogans as they demonstrate in Tahrir, or Liberation, Square in Cairo, Egypt, Tuesday, Feb. 1, 2011. More than a quarter-million people flooded into the heart of Cairo Tuesday, filling the city's main square in by far the largest demonstration in a week of unceasing demands for President Hosni Mubarak to leave after nearly 30 years in power.

Update 2:25 p.m. | Mubarak won’t seek re-election

Mubarak says he won’t run again. To which a heckling crowd, after watching the speech on TV in Tahir Square, chants “Get out, get out.” Mubarak’s speech called for “stability,” meaning an orderly transition, meaning Mubarak would not leave until after September elections. Stability probably isn’t the word most of the protesters were waiting to hear.

Protesters show the soles of their shoes, a grave insult in Arab Muslim countries, as a reaction after Egyptian president Hosni Mubarak says he would not step down immediately.

Some were suggesting this was Mubarak’s Lyndon Johnson moment, when Johnson said he wouldn’t run for re-election after his poor showing in the New Hampshire primary in 1968. That led, if you’ll remember, to the election of Richard Nixon. If the protests in Egypt continue, the question is whether Mubarak can hold on. Latest words from protesters were chants of “Not enough, not enough.”

Among my other sins, I'm a serial columnist. Over too many years to mention, I've written news columns, sports columns, features columns and op-ed columns. My first job was covering the Virginia Squires and Dr. J in the old American Basketball Association. I moved from the Virginian-Pilot to the Los Angeles Times, then to the Baltimore Sun, then to the late Rocky Mountain News and on to The Post.

A blog about whatever thoughts bounce through Mike Littwin's head — from politics to basketball (speaking of bouncing) to politics to books to politics to movies to politics to Sarah Palin (whenever I need the extra clicks).